Question 1040616
For each dollar price raised, the number sold decreases by 4.
For each dollar price lowered, the number sold increases by 4.
(30+x)(140-4x) would be the price*number factors.
4200+140x-120x-4x^2
-4x^2+20x+4200=0
the x value of the vertex is -b/2a or -20/-8 or 2.5
32.5 dollars and 130 widgets per day is maximum, or $4225
check with 33 dollars and 128 widgets $4224
or with 32 dollars and 132 widgets $4224
Graph is the product as a function of x.
{{{graph(300,200,-2,10,-200,4500,-4x^2+20x+4200)}}}